The Wheaton DC Metro station features the longest set of single-span escalators in the Western Hemisphere, each featuring a length of 230 feet (70 m), with a ve

The Wheaton DC Metro station features the longest set of single-span escalators in the Western Hemisphere, each featuring a length of 230 feet (70 m), with a vertical rise of 115 feet (35 m). The trip takes approximately 2 minutes and 45 seconds. Extrapolate that to a ~100m depth for a wait of 8 minutes 15 seconds, with a ~200m horizontal span that needs to be excavated manually all the way to the surface - you probably need one to two city blocks of demolition for a 30deg escalator. There are some high-speed elevators out there, at these heights we're strongly limited by comfortable acceleration (at the highest peak speeds from Mitsubishi or Toshiba you'd be talking about upwards of ~15m/s, but you couldn't safely reach those at this height). 1m/s^2 seems to be okay. That puts a half a trip at 10 seconds, or 20 seconds from when the doors finish closing to when the doors begin opening. Figure 25 seconds on either end for filling and emptying, and you have a 90 second round trip. Expect something like 4 20-person elevators for typical stops, to maybe 16 for an inner-city transfer station, and you can move 50-200 people per minute. According to Metro, a single escalator can move 90 people per minute; They typically pack 2 escalators and a stairwell, or 3 escalators running 2-1 peak flow, into a shaft, but escalator availability ran as low as 60 percent for a number of decades before a recent improvement drive (now ~92%), so you had good odds that at least one was broken (or, in optimistic parlance, 'had become stairs').